Skip to main content
SpringerLink
Log in

Effects of mandatory salt iodization on breast milk, urinary iodine concentrations, and thyroid hormones: is iodine deficiency still a continuing problem?

  • Original Article
  • Published:
Journal of Endocrinological Investigation Aims and scope Submit manuscript

Abstract

Purpose

To investigate whether mandatory use of iodized salt in Turkey, since 1999 has sufficient effects on pregnant women and their newborns’ urinary iodine concentrations (UIC), maternal and newborns’ thyroid function tests and breast milk iodine concentrations (BMIC).

Methods

This cross-sectional analytical-type study was conducted in an obstetrics and gynecology hospital in Konya, Turkey. One hundred and seven pregnant women and their 107 full-term newborns were included into the study. Levels of pregnant women and their newborns’ UIC, thyroid-stimulated hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), thyroglobulin (Tg), and BMIC were studied.

Results

Of 107 women with term pregnancy, mean TSH value and hypothyroidism frequency were found as 2.34 ± 1.33 mIU/L and 18.7%, respectively. Cord blood TSH level was found higher (≥ 10 mIU/L) in five newborns. Accordingly, the incidence of transient congenital hypothyroidism was 4.7% (5/107). Tg levels were observed to be higher in 50.5% of newborns and 22.4% of pregnant women. Frequency of iodized salt use in pregnancies was detected as 96.3% in general population, 97.5% in urban, and 92.9% in rural areas. Of pregnancies and newborns, 57.9 and 53.3% were found to have deficient urinary iodine, respectively, and BMIC deficiency was detected as 52.0%. There was a significant positive correlation between pregnant women’s UIC, and newborns’ UIC and BMIC.

Conclusions

Despite the effective struggle with iodine deficiency and salt iodination control program in Konya, we concluded that iodine deficiency still persists as a significant problem in pregnancies.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

References

  1. Karajewski AD, Burman KD (2011) Thyroid disorders in pregnancy. Endocrinol Metab Clin North Am 40(4):739–763

    Article  CAS  Google Scholar 

  2. Zimmermann MB, Jooste PL, Pandav CS (2008) Iodine-deficiency disorders. Lancet 372(9645):1251–1262

    Article  CAS  Google Scholar 

  3. Kurtoglu S, Akcakus M, Kocaoglu E, Gunes T, Budak N, Ataberk ME et al (2004) Iodine status remains critical in mother and infant in Central Anatolia (Kayseri) of Turkey. Eur J Nutr 43:297–303

    Article  CAS  PubMed  Google Scholar 

  4. Can G, Otken A, Green J (2001) The role of local mass media in promoting the consumption of iodized table salt. Health Educ Res 16(5):603–607

    Article  CAS  PubMed  Google Scholar 

  5. Yordam N, Ozon A, Alikasifoglu A, Ozgen A, Ceren N, Zafer Y et al (1999) Iodine deficiency in Turkey. Eur J Pediatr 158:501–505

    Article  CAS  PubMed  Google Scholar 

  6. Pino S, Fang SL, Braverman LE (1998) Ammonium persulfate: a new and safe method for measuring urinary iodine by ammonium persulfate oxidation. Exp Clin Endocrinol Diabetes 106(Suppl 3):22–27

    Google Scholar 

  7. Stagnaro-Green A, Abalovich M, Alexander E, Azizi F, Mestman J, Negro R, American Thyroid Association Taskforce on Thyroid Disease During Pregnancy and Postpartum et al (2011) Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid 21:1081–1125

    Article  PubMed  PubMed Central  Google Scholar 

  8. Delange F (1998) Screening for congenital hypothyroidism used as an indicator of the degree of iodine deficiency and of its control. Thyroid 8:1185–1192

    Article  CAS  PubMed  Google Scholar 

  9. Burtis CA, Ashwood ER, Bruns David E. Tietz textbook of clinical chemistry and molecular diagnostics. Edition 5. Elsevier Saunders; 2012

  10. Alan HBW. Tietz Laboratory Tests Clinical Guide. Kaya Emerk. Edition 4. Solar Medicine Bookstores; 2011:1046–49

  11. Caron P, Hoff M, Bazzi S, Dufor A, Faure G, Ghandour I et al (1997) Urinary iodine excretion during normal pregnancy in healthy women living in the southwest of France: correlation with maternal thyroid parameters. Thyroid 7:749–754

    Article  CAS  PubMed  Google Scholar 

  12. Delange F, Fisher DA (1995) The thyroid gland. In: Brook CGD (ed) Clinical pediatric endocrinology. Blackwell Sci Ltd, Cambridge, pp 397–433

    Google Scholar 

  13. WHO, The United Nations Children’s Fund (UNICEF), ICCIDD. Assessment of iodine deficiency disorders and monitoring their elimination. A guide for programme managers, Edition 3. Geneva, DSÖ 2007

  14. Semba RD, Delange F (2001) Iodine in human milk: perspectives for infant health. Nutr Rev 59:269–278

    Article  CAS  PubMed  Google Scholar 

  15. Bastug O, Korkmaz L, Halis H, Memur S, Korkut S, Ozdemir A et al (2017) Thyroid status of iodine deficient newborn infants living in central region of Turkey: a pilot study. World J Pediatr. 13:479–484

    Article  CAS  PubMed  Google Scholar 

  16. Iodine Global Network. 2016 statistics at a glance. http://www.ign.org. Accessed 20 Sep 2016

  17. Global Iodine Scorecard. [demographic map]. Raleigh: The International Council for Control of Iodine Deficiency Disorders (ICCIDD). 2015. http://www.ign.org/cm_data/Global_map_2014-2015_2.png

  18. Azizi F (2007) Iodine nutrition in pregnancy and lactation in Iran. Public Health Nutr. 10(12A):1596–1599

    Article  PubMed  Google Scholar 

  19. Oral E, Aydogan Mathyk B, Aydoğan BI, Acıkgoz AS, Erenel H, Acıoglu Celik H et al (2016) Iodine status of pregnant women in a metropolitan city which proved to be an iodine-sufficient area. Is mandatory salt iodisation enough for pregnant women? Gynecol Endocrinol 32(3):188–192

    Article  CAS  PubMed  Google Scholar 

  20. Leung AM, Pearce EN, Braverman LE (2009) Iodine content of prenatal multivitamins in the United States. N Engl J Med 360:939–940

    Article  CAS  PubMed  Google Scholar 

  21. Andersson M, Takkouche B, Egli I, Allen HE, de Benoist B (2005) Current global iodine status and progress over the last decade towards the elimination of iodine deficiency. Bull World Health Organ 83(7):518–525

    PubMed  PubMed Central  Google Scholar 

  22. Ordookhani A, Pearce EN, Hedayati M, Mirmiran P, Salimi S, Azizi F et al (2007) Assessment of thyroid function and urinary and breast milk iodine concentrations in ealthy newborns and their mothers in Tehran. Clin Endocrinol (Oxf) 67:175–179

    Article  CAS  Google Scholar 

  23. Pearce EN, Leung AM, Blount BC, Bazrafshan HR, He X, Pino S et al (2007) Breast milk iodine and perchlorate concentrations in lactating Boston-area women. J Clin Endocrinol Metab 92(5):1673–1677

    Article  CAS  PubMed  Google Scholar 

  24. Andersen SL, Møller M, Laurberg P (2014) Iodine concentrations in milk and in urinary during breastfeeding are differently affected by maternal fluid ıntake. Thyroıd 24(4):764–772

    Article  CAS  PubMed  Google Scholar 

  25. Anaforoğlu İ, Algün E, İnceçayır Ö, Topbaş M, Erdoğan MF (2016) Iodine status among pregnant women after mandatory salt iodisation. Br J Nutr 115(3):405–410

    Article  CAS  PubMed  Google Scholar 

  26. Kut A, Gursoy A, Senbayram S, Bayraktar N, Budakoglu II, Akgun HS (2010) Iodine intake is still inadequate among pregnant women eight years after mandatory iodination of salt in Turkey. J Endocrinol Invest 33(7):461–464

    Article  CAS  PubMed  Google Scholar 

  27. Najafi M, Khodaee GH, Bahari M, Sabahi M, Farsi MM, Kiani F (2008) Neonatal thyroid screening in a mild iodine deficiency endemic area in Iran. Indian J Med Sci 62:113–116

    Article  PubMed  Google Scholar 

  28. Nohr S, Laurberg P (2000) Opposite variations in maternal and neonatal thyroid function ınduced by ıodine supplementation during pregnancy. J Clin Endocrinol Metab 85(2):623–627

    CAS  PubMed  Google Scholar 

  29. Findik RB, Yilmaz G, Celik HT, Yilmaz FM, Hamurcu U, Karakaya J (2014) Effect of povidone iodine on thyroid functions and urine iodine levels in caesarean operations. J Matern Fetal Neonatal Med. 27(10):1020–1022

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We wish to thank the Necmettin Erbakan University Scientific Research Coordination Center (BAP) for the financial support to this study. We also thank to the mothers and their infants for their participation in this study.

Author information

Authors and Affiliations

  1. Department of Family Medicine, Güzelyurt District Government Hospital, Aksaray, Turkey

    D. Isiklar Ozberk

  2. Department of Family Medicine, Meram Medical Faculty, University of Necmettin Erbakan, Konya, Turkey

    R. Kutlu

  3. Department of Clinical Biochemistry, Meram Medical Faculty, University of Necmettin Erbakan, Konya, Turkey

    I. Kilinc

  4. Department of Family Medicine, Karatay Fetih Family Health Center, Konya, Turkey

    A. O. Kilicaslan

Authors
  1. D. Isiklar Ozberk
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. R. Kutlu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. I. Kilinc
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. A. O. Kilicaslan
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to D. Isiklar Ozberk.

Ethics declarations

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical approval

This study was planned according to the Helsinki Declaration and was approved by the Ethics Board of Necmettin Erbakan University (approval number: 2013/29).

Informed consent

All pregnant women were informed about the study design, and oral and written informed consent was obtained from all individual participants included in the study.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Isiklar Ozberk, D., Kutlu, R., Kilinc, I. et al. Effects of mandatory salt iodization on breast milk, urinary iodine concentrations, and thyroid hormones: is iodine deficiency still a continuing problem?. J Endocrinol Invest 42, 411–418 (2019). https://doi.org/10.1007/s40618-018-0930-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40618-018-0930-0

Keywords

Search

Navigation